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R. C. COLE.

CARTRIDGE FUSE.y

APPLCATION FILED 1AN.21.1919.

1,309,508. Patented July 8, 1919.

- Z'r/ Ven fr WC CL4, f /a/uy/fm'... A 1' far/veg GARTRID @l To El whom it' may concern:

Be it known that I, Roniiirr C. COLE, a citizen of the llnited States, residing at Hartl-"ord, in the county of Hartford and State of Connecticut, haveinvented a newl and useful Improvement in CartridgeFuses, of which the following is a specification.

This invention relates to the construction of those inclosed electric safety fuses of the cartridge type which are more particularly designed for the protection of delicate apparatus, such as multiple motor controls, using small currents, for example, l to 3 amperes, that are connected with light and power circuits of common commercial pressures, for instance 250 and 600 volts. Owing to the small capacity of such fuses the fusible link is very delicate, that, for illustration, of a 600 volt, 1 ampere fuse, if o Zinc wire would be approximately 2.5 inches long and .0028 of an inch in diameter. These fuses must be accurately calibrated and must be durable,'and the allowable interval between safe load and blow must be small, otheiwiseeither they would not perform their functions as safety devices or they would open prematurely and cause great annoyance.y Very slight variations in dimension, construction, and arrangement of the elements effect greater proportional changes in the carrying capacity and bloW- ing time of vthese small fuses than in fuses of larger capacity. Furthermore, these devices must be capable of being manufactured in considerable quantities at a reasonable cost.

It has been customary to solder the ends of the fusible links to the termina-ls and connect Ithese terminals with conducting caps on the ends of a tubular insulating case and to fill the case with a granular compound designed to absorb and condense the gases and flash. incident to the blowing of the fuse. Soldering such joints necessitates the use of flux. Heat of the solder frequently melts the ends or these delicate links, and the linx if not entirely removed causes a local bat tery action at the ioints alter the'case has been filled. Under these conditions the links are sooner or later renderedv entirely ineffective or their carrying capacity is altered so that l fuses are not u .iforin and reliable. fact. iii the construction previously t iloyed, c high itage of these small fases are rei red inenectivc a re" naar c. com, or HARTFORD, comme company', or Hanrrcnn, connnc'ri Specification or' Letters Patent.

Application filed January 2, i919.

lil-FUSE,

)Patented lluly 8, i919.

Serial No. 27.253584.

snlt of soldering the links to the terminals,

even with the exercise or' care in their manufacture. Moreover, in the prior structures it is diiiicult to handle without breaking, and lieep straight and in the center of the case, such very delicate '.ruse links, and their condition in this respect affects the load and blowing interval.

The object of this invention is to provide a construction for such small capacity fuses which renderssoldering of the delicate links to the terminals unnecessary, thus eliminating the dangerot melting the links or subsequent deterioration from galvanic action, and which permits the fuse links to be handled rapidly and quickly assembled in large quantities, straight and in the center of the case, thus insuring accurate and reliable fuses of small capacity at minimum cost.

Figure l of the accompanying drawings shows a central longitudinal section of a fuse constructed according to this invention. Fig. 2 is a View looltinoat one end with the metal end cap removed from the insulating case. .F ig. 3 is a view of the insulating strut upon which is mounted the delicate tusible link.

The tubular case l is made of insulating ma.- terial and'providetl with metal end caps 2 in the usual manner. .lioosely located in the case and extending longitudinally thereof?l is astrip of insulating material 3 that has projections or feet-Lt which extend diametrically across the case some distance apart. This piece which .may be termed a strut is desirab'ly punched or cut to shape from stiff paper, ber or the like sheet insulating material. The fine fusible linlr 5, ordinarily round zinc wire, is mounted on this strut. 'the feet -i of the strut are preferably notched and the ends of the link 5 are wrapped about the notched sections, after which the inner ends of the termina 6, ordinarily soft copper wire, are wrapped abont the notched sections ci' the strut feet, over the wound ends of the fusible linliz.

The insulating strut is inade slightly shorter than the length of the case'and a litless in width thar the case,a`nd the no ies in the feet so positioned 'that the linlr and ininal wires mi,v extend substantially in the longitudinal ine inner diameter ol perforations in the end caps and their outer ends` are connected therewith in the usual Way, preferably by solder. Before the second end 'ap is placed in position, the ease may be lled with the granular material 7 commonly used for absorbin and condensing the gases and thune resu ting from the blowing of the fuse.

This construction enables uniformly accurate and reliable small capacity fuses haiinr very delicate fusible links to be manufactured in large quantities, rapidly, and efipensii'ely Without the exercise of extreme care.

' he invention claiined is:

l* A cartridge fuse having an insulating case, inet-al caps at the ends et the case, a piece of sheet insulation loosely located in the case and extending longitudinall)v and transversely thereof9 a fusible Wire estending between and having its ends Wrapped about portions ot said piece ot insulation, and terminal n" es vwith their inner ends Wrapped about the inner ends o1- the fusible Wire and their outer ends electrically con nected with the end caps.

il cartridge fuse having an insulatin case. metal caps at the ends ot die ease1 a insulating1 strip with proecting portions loosely located in the oase, a fusible Wire stretched between and haring its ends Wrapped about the projecting portions of the insulating strip, and terminal Wires with their inner ends Wrapped about the projecting portions ot tl insulating strip and inner ends of the fusible wire and with their outer ends electrically connected with the end caps.

3, cartridge fuse having an insulating case, metal caps at the ends ot the case, a strip of sheet insulation extending longitudinally in the inte-rior ol' the case With projections therefroin extending diametrically across the interior ot the ease, said projections havingnotches in their edges in line with the axis of the case, a fusible Wire with its ends wrapped about the notched sections ot said insulating piece, and terminal Wires with their inner ends Wrapped about the ends ot said fusible Wire and with their outer ends electrically connected with the end caps.

l. lin element tor a cartridge tuse coinprising, a strip ot sheet insulation with por tions projectingl therefrom, a Wliusible Wire stretched between and having its ends wrapped about the proiectingportions ot the insulating strip, and terminal wires with ends u'raoped about thel project portions of the insulating strip and ends in ble nire.

li-lfllllfl C. COLE.

the t'usi- 

